JP2013534082A - Active antenna array and method for relaying radio signals - Google Patents

Abstract

  According to the present disclosure, an active antenna array for a mobile communication network is taught. The active antenna array includes a baseband unit, a plurality of transmission / reception units terminated by at least one antenna element, and at least one link. The link couples each of the plurality of transceiver units to the baseband unit. The link is a digital link and is configured to relay the payload signal at a selectable payload rate. The digital link is further configured to relay the timing signal at a fixed timing rate, at which time the timing signal is embedded in the payload at a selectable payload rate. The present disclosure further teaches a method for relaying radio signals, a computer program for manufacturing an active antenna array, and a computer program for performing the method.

Description

This application claims the priority and benefit of US patent application Ser. No. 12 / 792,936, filed Jun. 3, 2010. This application relates to US patent application Ser. No. 12 / 577,339, “A RADIO SYSTEM AND A METHOD FOR RELAYING RADIO SIGNALS”, filed Oct. 12, 2009. The present application is named “ACTIVE ANTENNA ARRAY AND METHOD FOR RELAYING RADIO SIGNALS WITH SYNCHRONOUS DIGITAL DATA INTERFACE” filed at the same time as the present application. Also related to US patent applications. The entire disclosure of each of the aforementioned patent applications is incorporated herein by reference.

The field of the invention relates to an active antenna array for relaying radio signals. Furthermore, the field of the invention relates to a method for relaying radio signals in a mobile communication network. Further, the field of the invention is a computer program product that enables foundries to perform the manufacture of active antenna arrays, and a computer that enables a processor to perform a method for relaying radio signals in a mobile communication network. Regarding program products.

  The use of mobile communication networks has increased over the past decade. Mobile communication network operators are increasing the number of base stations in order to meet the increasing demand for services by users of mobile communication networks. The base station is typically coupled to an (active) antenna array. Radio signals are typically relayed into a cell of a mobile communication network and vice versa. For operators of mobile communication networks, it is of interest to reduce the running costs of base stations. Implementing the wireless system as a wireless system with an embedded antenna is one option. When a wireless system with embedded antennas is formed as an active antenna array, some of the hardware components of the wireless system can be implemented on a chip. Therefore, the cost of the base station is reduced by the active antenna array. By implementing the wireless system as a wireless system with embedded antennas, the space required to accommodate the base station hardware components is reduced. Implementing a wireless system with an embedded antenna substantially reduces power consumption during normal operation of the wireless system.

  Even as the number of users increases, it is of interest to provide reliable quality services to individual users of a mobile communication network. Several techniques have been proposed to deal with the increasing number of users in mobile communication networks. One of its several techniques includes the ability to form a beam to improve the service area within a cell of a mobile communication network by directing beams relayed by an active antenna array in various directions. Beamforming techniques rely on defined phase and amplitude relationships between several antenna elements of the active antenna array. The transmission path and / or the reception path is associated with at least one antenna element. To calibrate the transmission path and / or the reception path, it is necessary to give a defined phase, amplitude and delay relationship between the respective antenna elements. Calibration allows estimation of phase, amplitude and delay deviations accumulated along the individual transmission paths of the active antenna array. Similarly, calibration includes estimating the phase, amplitude and delay deviations accumulated along each receive path. In the second step, phase, amplitude and delay deviations accumulated along the transmission path can be corrected. Appropriate phase and amplitude changes are applied to the individual transmit / receive paths to enable a beamforming technique to establish a defined phase and amplitude relationship between the individual transmit / receive paths of the active antenna array. It may be generated.

  In a recent mobile communication network, a payload signal is given to an active antenna array as a packetized payload signal. The packetized packet of payload signals has a defined temporal order when the packetized payload signal is applied to the digital radio interface. Some (data) processing within the active antenna array may be added to the packetized payload signal. The (data) processing typically involves the packetized payload signal passing through several buffers and a clock domain synchronized by the PLL. The data processing may be used to change the timing of the packet stream each time the system is restarted (reset). In the prior art, it is possible to use a non-packetized signal to calibrate the transmission path along which the non-packetized payload signal travels when relayed by the radio station during radio station manufacturing It was customary.

  The delay experienced by a radio signal reaching the digital radio interface until the corresponding radio signal is relayed by the antenna element of the active antenna array is interesting for matching the relay of the active antenna array. The delay affects the phase relationship between the respective antenna elements and the position based service. The delay is affected by any change such as cable length.

  In the prior art, each time an active antenna array component, eg, a cable, was replaced, the active antenna array had to be recalibrated. Prior art recalibration is expensive and time consuming.

  US Pat. No. 6,693,588 (assigned to Siemens) discloses a group antenna with electronic phase control. Electronically phase controlled group antennas are calibrated using a reference point shared by all reference signals. In the downlink, reference signals that can be distinguished from each other are transmitted simultaneously by the individual antenna elements of the group antenna and received at the shared reference point, and then separated appropriately.

  In the Siemens system of US Pat. No. 6,693,588, a fixed spatial arrangement of antenna elements is disclosed.

  FIG. 1a shows a passive antenna array 1a according to the prior art. Base station 5 provides base station signal 7 to passive antenna array 1a. The digital interface transmits the base station signal 7 between the base station 5 and the central baseband processing unit 10 of the passive antenna array 1a. The central baseband processing unit 10 transfers the transmission signal Tx to the power amplifier 60 in order to amplify the transmission signal Tx. It will be appreciated that the transmission signal Tx is typically provided in the transmission band of a mobile communication system. The signal leaving the central baseband unit 10 is an analog domain transmission signal. The transmission signal Tx entering the amplifier 60 needs to be up-converted to the transmission band of the passive antenna array 1a. If the transmission signal Tx is in the digital domain, the transmission signal Tx needs to be further converted from digital to analog. The digital / analog conversion is performed by a digital / analog converter (not shown) before amplification by the amplifier 60. The analog transmission signal leaving the amplifier 60 is transferred to the individual transmission paths. Each transmission path transmits an analog transmission signal to an individual antenna element 85-1, 85-2,. . . , 85-N to duplex filters 25-1, 25-2,. . . , 25-N. More than one individual antenna element 85-1, 85-2,. . . , 85-N are connected to individual duplex filters 25-1, 25-2,. . . , 25-N. Individual duplex filters 25-1, 25-2,. . . , 25-N, the analog transmission signal passes through the passive power supply network 40a. The passive power supply network 40a allows each antenna element 85-1, 85-2,. . . , 85-N, a fixed phase, amplitude and / or delay relationship is imposed between the respective transmission paths. The passive power supply network 40a has little flexibility in terms of beam shaping. No matter how the components change in the passive power supply network 40a, each duplex filter 25-1, 25-2,. . . , 25-N need to be recalibrated. Each transmission path is connected from the amplifier 60 to the passive power supply network 40a and the individual duplex filters 25-1, 25-2,. . . , 25-N extending across the individual antenna elements 85-1, 85-2,. . . , 85-N.

  Individual reception paths of the passive antenna array 1a include individual antenna elements 85-1, 85-2,. . . , 85-N to duplex filters 25-1, 25-2,. . . 25-N and the passive power supply network 40a, and reaches the reception amplifier 70 as a comprehensive reception signal Rx. The comprehensive received signal Rx is received by antenna elements 85-1, 85-2,. . . , 85-N are combined from the individual received signals by the passive power supply network 40a. Each antenna element 85-1, 85-2,. . . , 85-N, a fixed phase, amplitude and delay relationship is imposed between the received signals. Therefore, the beam forming capability for each received signal is limited by the passive power supply network 40a.

  The received signal Rx is in the analog domain. Individual received signals from the antenna elements are coupled to duplex filters 25-1, 25-2,... As known in the art. . . , 25-N. The reception signal Rx is amplified by the reception amplifier 70 and converted from analog to digital by using an analog-to-digital converter (not shown), for example, a sigma-delta analog-to-digital converter. The signal reaching the central baseband processing unit 10 from the reception amplifier 70 is typically in the baseband of the passive antenna array 1a. The received signal from the receiving amplifier 70 may be in an intermediate frequency band between the baseband of the passive antenna array 1a and the transmission band of the passive antenna array 1a. The central baseband processing unit 10 may impose some kind of digital signal processing such as filtering on the digital received signal, and transfers the digital received signal in the baseband to the base station 5.

  FIG. 1b shows a variant of the active antenna array 1a according to the prior art. A system as shown in FIG. 1b is typically equivalent to combining a prior art remote radio head (RRH) with a known base station antenna in a common housing. Base station signal 7 includes the received signal from central baseband processor 10, which is forwarded to base station 5. In FIG. 1b, the duplex filters 25-1, 25-2,. . . , 25 -N are replaced by one duplexer 25. It will be appreciated that the system of FIG. 1b is more cost effective than the system shown in FIG. 1a.

  Transmission signals and reception signals between the base station 5 and the central baseband processing unit 10 are transferred along the digital interface. The transmission signal and / or the reception signal may be given by an in-phase component I and a quadrature component Q. The in-phase component I and the quadrature component Q may be given according to a standard format defined by an open base station architecture interface (OBASI) or according to a format of a common protocol radio interface (CPRI), but is not limited thereto.

  FIG. 2 shows an active antenna array 1a according to the prior art. The active antenna array 1a in FIG. 2 does not include the passive power supply network 40a as shown in FIG. Instead, antenna elements 85-1, 85-2,. . . , 85-N are transmission / reception units 20-1, 20-2,. . . , 20-N. The transmission / reception units 20-1, 20-2,. . . , 20-N are transceiver units 20-1, 20-2,. . . , 20-N, amplifiers 60-1, 60-2,. . . , 60-N. Similarly, the transmission / reception units 20-1, 20-2,. . . , 20-N are transceiver units 20-1, 20-2,. . . , 20-N for each receive amplifier 70-1, 70-2,. . . , 70-N. The central baseband processing unit 10 includes individual transmission signals Tx-1, Tx-2,. . . , Tx-N from the central baseband unit 10 to the individual amplifiers 60-1, 60-2,. . . , 60-N. Individual transmission signals Tx-1, Tx-2,. . . , Tx-N are typically in the analog domain and the transmission band of the active antenna array 1a. Typically, the digital / analog conversion is performed by the central baseband processing unit 10 as described above. Individual antenna elements 85-1, 85-2,. . . , 85-N are received signals received by individual receiving amplifiers 70-1, 70-2,. . . , 70-N and the individual received signals Rx-1, Rx-2,. . . , Rx-N are transferred to the central baseband processing unit 10. The individual received signals Rx-1, Rx-2,. . . , Rx-N are combined by the central baseband processing unit 10. The individual received signals Rx-1, Rx-2,. . . , Rx-N combination is performed in the baseband region. The individual received signals Rx-1, Rx-2,. . . , Rx-N are in the analog domain. The central baseband processing unit 10 typically performs analog / digital conversion. The central baseband processing unit 10 includes individual received signals Rx-1, Rx-2,. . . , Rx-N are combined into one global received signal. The global received signal is typically transferred to the base station 5.

  Individual transmission signals Tx-1, Tx-2,. . . , Tx-N are in the analog region and the transmission band of the active antenna array 1a. Individual transmission signals Tx-1, Tx-2,. . . , Tx-N are generated by the central baseband processing unit 10. Individual transmission signals Tx-1, Tx-2,. . . , Tx-N may be performed in the digital domain or the analog domain. An active antenna array 1a as shown in FIG. 2 is known from, for example, a radar (RADAR) application or a phased array antenna used for a magnetic resonance image.

  The phased array antenna 1a can also be configured for reception. The individual received signals Rx-1, Rx-2,. . . , Rx-N are connected to individual receiving amplifiers 70-1, 70-2,. . . , 70 -N and combined with the comprehensive received signal by the central baseband processing unit 10. The combination into a comprehensive received signal may be performed in the digital domain and / or the analog domain. However, in order to operate such a phased array, that is, the active antenna array 1a as shown in FIG. 2, in order to relay the target beam by the active antenna array 1a, each transmitting / receiving unit 20-1, 20-2,. . . , 20-N must be carefully calibrated for phase, amplitude and delay relationships. If the embodiment of the active antenna array 1a is constructed substantially in the analog domain, the calibration of the active antenna array 1a is difficult and the known solutions are often bulky, cumbersome and expensive.

  The present invention relates to an active antenna array for a mobile communication network. The active antenna array includes a baseband unit, a plurality of transmission / reception units, and at least one link. The baseband unit is coupled to the base station 5. The plurality of transmission / reception units are terminated by at least one antenna element. Thus, each transceiver may be terminated with more than one antenna element. At least one link couples each of the plurality of transceiver units to the baseband unit. At least one link is a digital link and is configured to relay the payload signal at a selectable payload rate. The at least one link is further configured to relay the timing signal at a fixed timing rate. The timing signal T is embedded in the pilot signal at a selectable payload rate.

  The invention further relates to a method for relaying a radio signal in a mobile communication network. The method includes generating a global timing signal at a fixed timing rate. The global timing rate is generated in response to a payload signal received from the base station. The method includes embedding a global timing signal in at least one payload signal at a selectable payload rate. The method further includes transferring at least one payload signal across at least one link. The method further includes extracting at least one local timing signal for at least one transceiver from the global timing signal. The method further includes relaying at least one payload signal according to individual local timing signals. The selectable payload rate can be selected independently of the next timing rate.

  Furthermore, the present disclosure relates to a computer program product that includes a non-transitory computer-usable medium having control logic stored therein for causing the computer to manufacture an active antenna array for the mobile common network of the present disclosure.

  Furthermore, the present disclosure relates to a computer program product comprising a non-transitory computer-usable medium having control logic stored therein for causing a computer to relay a wireless signal within a mobile communication network disclosed by the present disclosure. .

1 illustrates a prior art active antenna array. 2 shows a variation of a prior art active antenna array. 2 shows another aspect of an active antenna array according to the prior art. 1 shows a first embodiment of an active antenna array. 3 shows another aspect of an active antenna array. 1 shows an active antenna array 1 with a feedback path. Fig. 4 illustrates another aspect of an active antenna array with a feedback path. The measured values of amplitude deviation and phase deviation at discrete frequencies are shown. The concept of pre-emphasis for compensating the transmission phase in the band is shown. Fig. 4 shows equalization to compensate for in-band received phase. FIG. 2 shows a diagram of a method for relaying radio signals. A diagram of the steps for compensating for the deviation is shown.

  Now, the present invention will be described with reference to the drawings. It will be understood that the embodiments and aspects described herein are exemplary only and do not limit the scope of protection of the claims in any way. The invention is defined by the claims and their equivalents. It will also be appreciated that features of one aspect can be combined with features of another aspect.

  FIG. 3 shows an active antenna array 1 according to the present disclosure. As will be described below, the transceivers 20-1, 20-2,. . . , 20-N are provided with individual clocks, the active antenna train 1 is different from the current highest level active antenna train 1a (see FIGS. 1 and 2). In FIG. 3, links 40-1, 40-2,. . . , 40-N are connected to the central baseband processing unit, i.e., the baseband unit 10, with the respective transmitting / receiving units 20-1, 20-2,. . . , 20-N. Therefore, the individual transmission signals Tx-1, Tx-2,. . . , Tx-N are transmitted / received units 20-1, 20-2,. . . , 20-N and are no longer in the analog domain (as can be seen from FIGS. 1 and 2). Similarly, the transmission / reception units 20-1, 20-2,. . . , 20 -N are also in the digital domain when transferred to the central baseband processor 10. Links 40-1, 40-2,. . . , 40-N are digital links. Central baseband processing unit 10 and transmission / reception units 20-1, 20-2,. . . , 20-N links 40-1, 40-2,. . . , 40-N are asynchronous. Data is exchanged using variable length data frames or packet sizes. There is no constant bit stream synchronized with the digital payload signal or base station signal 7.

  Links 40-1, 40-2,. . . , 40-N each has a respective payload signal P-1, P-2,. . . , PN is relayed. The selectable payload rate may be implemented using a variable packet size. The base station 5 transfers a data stream that includes a base station signal 7 that is typically at a constant sampling rate. Individual links 40-1, 40-2,. . . , 40-N payload rate Pr can be selected. The payload rate Pr is determined by the individual links 40-1, 40-2,. . . , 40-N may change over time.

  Individual links 40-1, 40-2,. . . , 40-N to relay the first packet with the first packet size and the same individual link 40-1, 40-2,. . . , 40-N, the second packet may be relayed with the second packet size. Therefore, the links 40-1, 40-2,. . . , 40-N maximum payload rate subdivision can also be implemented. Maximum payload rate subdivision can be implemented using different packet sizes. When using various packet sizes, the links 40-1, 40-2,. . . , 40-N enables burst-type transmission. The maximum payload rate is the link 40-1, 40-2,. . . , 40-N may be 2.4 Gb / s, but is not limited thereto. When relaying a radio signal using the active antenna array 1 according to more than one protocol, the maximum payload rate and the links 40-1, 40-2,. . . , 40-N, a fraction of the maximum payload rate can be used.

  The base station signal 7 includes a clear temporal sequence of data frames or data packets throughout the digital interface that reaches the central baseband processor 10. Links 40-1, 40-2,. . . , 40-N along the individual payload signals P-1, P-2,. . . , P-N payload rate is variable and therefore does not necessarily reflect the temporal order of base station signals 7 throughout the digital interface. Links 40-1, 40-2,. . . , 40-N, introduces a delay in the base station signal 7 or removes a delay in the base station signal 7, thereby disturbing the temporal order of the base station signal 7. There is a risk. In order to match the relay by the active antenna array 1, each of the transmission / reception units 20-1, 20-2,. . . 20-N, it is of interest to restore the temporal order of digital data packets.

  Individual payload signals P-1, P-2,. . . , PN are individual transmission signals Tx-1, Tx-2,. . . , Tx-N. Individual payload signals P-1, P-2,. . . , PN further includes individual received signals Rx-1, Rx-2,. . . , Rx-N. In the active antenna array 1a of FIGS. 1 and 2, the digital-to-analog conversion is performed by the central baseband processing unit 10 together with any other signal processing. The active antenna array 1 in FIG. 3 includes processing elements 95-1, 95-2,. . . , 95-N. Processing elements 95-1, 95-2,. . . , 95-N are configured to perform signal processing on the digital signal and / or form the digital signal (s) from the analog signal. Processing elements 95-1, 95-2,. . . , 95-N can be digital filter elements, analog filter elements, duplex filters, digital / analog converters, analog / digital converters, equalizers, mixers, but is not limited thereto.

  Individual payload signals P-1, P-2,. . . , P-N variable payload rate Pr is determined by links 40-1, 40-2,. . . , 40-N on the clock. When changing the payload rate Pr, the frequency of the clock generator, the transmitting / receiving units 20-1, 20-2,. . . , 20-N or a distributed flexible clocking scheme that does not require modification of the central baseband processor 10 is taught by this disclosure. Therefore, the individual payload signals P-1, P-2,. . . , P-N, a high degree of flexibility is realized by the active antenna array 1 when changing the respective payload rates Pr. Even if the payload rate Pr is changed, the frequency of the clock generator, the transmitting / receiving units 20-1, 20-2,. . . , 20-N or the central baseband processing unit 10 need not be modified at all.

  Payload signals p-P-1, p-P-2,. . . , P-P-N embeds the global timing signal T so that the rising edge and / or falling edge of the global timing signal T substantially occur at a defined frequency representing the timing rate Tr. Can be realized by encoding.

  The central processing unit 10 and the individual transmitting / receiving units 20-1, 20-2,. . . , 20 -N are synchronized using a global timing signal T embedded in the base station signal 7. The global timing signal T is transmitted from the links 40-1, 40-2,. . . , 40-N, the individual payload signals p-P-1, p-P-2,. . . , P-P-N.

  4 shows transmission / reception units 20-1, 20-2,. . . , 20-N for each timing signal T-1, T-2,. . . , TN synchronization is disclosed in more detail. The timing signal T is typically given at a fixed timing rate Tr. The timing signal T is extracted from the base station signal 7 by the central clock unit 50. The central clock unit 50 sends the timing signal T to the links 40-1, 40-2,. . . , 40-N. More precisely, the timing signal T comprises individual payload signals P-1, P-2,. . . , P-N data package.

  The transmission / reception units 20-1, 20-2,. . . , 20-N are local timing units 55-1, 55-2,. . . , 55-N. The local timing units 55-1, 55-2,. . . , 55-N are individual payload signals P-1, P-2,. . . , PN to local timing signals T-1, T-2,. . . , TN are taken out and the links 40-1, 40-2,. . . , 40-N.

  The local timing units 55-1, 55-2,. . . 55-N, it will be understood that the timing rate Tr of the global timing signal T is known. In combination with buffers (not shown), the links 40-1, 40-2,. . . , 40-N, the temporal order of data packets relayed along the local timing units 55-1, 55-2,. . . , 55-N, local timing signals T-1, T-2,. . . , T-N. Therefore, the time order of the digital base station signal 7 is determined by the transmitting / receiving units 20-1, 20-2,. . . , 20-N can be restored.

  Due to the distributed clock synchronization concept described in the present disclosure, each of the transmission / reception units 20-1, 20-2,. . . , 20 -N can be synchronized with the central clock unit 50 of the baseband processing unit 10. Under perfect conditions, all the transceivers 20-1, 20-2,. . . , 20-N are brought about simultaneously. However, due to different cable lengths, the impact of launching digital components such as buffers, and tolerances of analog components such as group delay variations, distributed clock synchronization is associated with each transceiver 20- 1, 20-2,. . . , 20-N. Due to all these influences, the respective transmitting / receiving units 20-1, 20-2,. . . , 20-N can cause variations in time delay, amplitude and phase.

  As will be described below, the individual transmitting / receiving units 20-1, 20-2,. . . , 20-N, means for measuring phase deviation, amplitude deviation and delay deviation, and transceivers 20-1, 20-2,. . . , 20-N due to the incompleteness of the respective transmitting / receiving units 20-1, 20-2,. . . , 20-N, techniques for compensating for phase, amplitude and delay deviations are known in the art. It is known that phase deviations, amplitude deviations and time deviations can be measured using pilot signals and / or in a blinded manner. The blind method uses the payload signal from the base station signal 7 as antenna elements 85-1, 85-2,. . . , 85-N with a payload signal beam that is actually relayed. In the digital domain, correlation methods may be implemented as described in related US patent application Ser. No. 12 / 577,339 filed Apr. 1, 2009.

  FIG. 5 shows antenna elements 85-1, 85-2,. . . , 85 -N to feedback section 110-1, 110-2,. . . , 110-N, the aspect of the active antenna array 1 is shown. Feedback paths 110-1, 110-2,. . . , 110-N are feedback signals 120-1, 120-2,. . . , 120-N. Feedback signals 120-1, 120-2,. . . , 120-N are transceiver units 20-1, 20-2,. . . , 20-N combined transmission signals 120Tx-1, 120Tx-2,. . . , 120Tx-N. The combined transmission signals 120Tx-1, 120Tx-2,. . . , 120Tx-N are connected to antenna elements 85-1, 85-2,. . . , 85-N includes a small portion of the signal transmitted. The combined transmission signals 120Tx-1, 120Tx-2,. . . , 120Tx-N includes a directional coupler (not shown), but is not limited thereto. Feedback signals 120-1, 120-2,. . . , 120-N are connected to antenna elements 85-1, 85-2,. . . , 85-N, the combined received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N. Transmission signals 120Tx-1, 120Tx-2,... Combined with payload signals in the base station signal 7 entering the central baseband processing unit 10. . . , 120Tx-N, the transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N can be calculated. Transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N includes a transmission phase deviation, a transmission amplitude deviation, and a transmission time delay. Transmission deviations ΔTx-1, ΔTx-2,. . . , .DELTA.Tx-N are respectively transmitted / received units 20-1, 20-2,. . . , 20-N describes a certain amount of temporal mismatch.

  The combined received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N and the received signal in the base station signal 7 leaving the central baseband processing unit 10, the respective transmitting / receiving units 20-1, 20-2,. . . , 20-N, reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N is given. Reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N includes reception phase fluctuation, reception amplitude fluctuation, and reception delay fluctuation. Reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N and / or transmission deviations ΔTx−1, ΔTx−2,. . . , ΔTx−N are measured by the measurement unit 150. Transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N and / or reception fluctuations ΔRx−1, ΔRx−2,. . . , ΔRx−N are transferred to the central baseband processing unit 10.

  Adjustment units 90-1, 90-2,. . . , 90-N are configured to impose base compensation, amplitude compensation and delay compensation to match the relay of the active antenna array 1. Adjustment units 90-1, 90-2,. . . , 90-N are links 40-1, 40-2,. . . , 40-N before entering payload signals P-1, P-2,. . . , P-N, transmission compensation 200Tx-1, 200Tx-2,. . . , 200Tx-N. Transmission compensation 200Tx-1, 200Tx-2,. . . , 200Tx-N may include transmission phase compensation, transmission amplitude compensation, and transmission delay compensation. Transmission compensation 200Tx-1, 200Tx-2,. . . , 200Tx-N, transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N is substantially corrected. Therefore, the transmission of the active antenna array 1 is substantially matched. Further, the adjustment units 90-1, 90-2,. . . , 90-N are respectively transmitted / received units 20-1, 20-2,. . . , 20-N to receive compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N. Reception compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N includes reception phase compensation, reception amplitude compensation, and reception delay compensation. Reception compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N are received deviations ΔRx-1, ΔRx-2,..., As measured by the measurement unit 150 to match the reception of the active antenna array 1. . . , ΔRx−N is substantially compensated.

  By inserting wattmeters (not shown), transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N and / or reception deviations ΔRx−1, ΔRx−2,. . . , ΔRx−N, measuring the amplitude deviation is one option. The wattmeter includes transmission / reception units 20-1, 20-2,. . . , 20-N or central baseband processing unit 10 or feedback paths 110-1, 110-2,. . . , 110-N. The use of a wattmeter, such as a variable capacitance diode, is disclosed in Applicant's related patent application US patent application Ser. No. 12 / 577,339.

  In order to be able to perform phase calibration for the active antenna array 1, transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N and / or reception deviations ΔRx−1, ΔRx−2,. . . It will be appreciated that the phase deviation in ΔRx−N needs to be measured. The measurement of the phase deviation is performed by measuring the payload signals P-1, P-2,. . . , P-N, or by flowing a dedicated pilot signal. The dedicated pilot signal is transmitted to each of the transmitting / receiving units 20-1, 20-2,. . . , 20-N with certain characteristics that allow measurement of phase deviations, for example, individual transceivers 20-1, 20-2,. . . , 20-N, the individual payload signals P-1, P-2,. . . , P-N have specific correlation characteristics. Therefore, the respective transmitting / receiving units 20-1, 20-2,. . . , 20-N to identify individual payload signals P-1, P-2,. . . , PN can be recognized. Complex-valued payload signals P-1, P-2,. . . , PN may be multiplied by an appropriate complex factor to compensate for amplitude and phase deviations. Complex multiplication can be configured by a central baseband processing unit 10 as shown in FIG.

  Alternatively, as shown in FIG. 6, the transmission / reception units 20-1, 20-2,. . . , 20-N, phase compensation and amplitude compensation may be performed independently. In FIG. 6, the adjustment units 90-1, 90-2,. . . , 90-N are connected from the central baseband unit 10 to the transmitting / receiving units 20-1, 20-2,. . . , 20-N.

  Still another option for transmission amplitude compensation is that each transmission / reception unit 20-1, 20-2,. . . , 20-N transmission amplifiers 60-1, 60-2,. . . , 60-N analog gain. In the case of reception amplitude compensation, the individual reception amplifiers 70-1, 70-2,. . . , 70-N, receive amplifiers 70-1, 70-2,. . . , 70-N analog gain may be varied.

  Transmission deviation and / or reception deviation ΔTx-1, ΔTx-2,. . . , ΔTx−N, ΔRx−1, ΔRx−2,. . . , ΔRx−N to compensate for the phase deviation of the analog transmission amplifiers 60-1, 60-2,. . . , 60-N or analog receiving amplifiers 70-1, 70-2,. . . 70-N, an analog phase shift circuit may be used.

  Transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N and / or reception deviations ΔRx−1, ΔRx−2,. . . , ΔRx−N may be frequency dependent. Ideally, the transmission / reception units 20-1, 20-2,. . . , 20-N should exhibit a substantially “flat” frequency behavior in its signal transfer characteristics. Therefore, phase measurements and amplitude measurements should not be frequency dependent. The transmission / reception units 20-1, 20-2,. . . , 20-N have a “flat” transfer characteristic, and the transmission / reception units 20-1, 20-2,. . . , 20-N, it would be sufficient to measure the phase and amplitude deviations at one frequency in the ideal case where there is a perfect time alignment.

  In actual systems, this “flat” transfer characteristic requirement with respect to frequency is usually not met. The transfer characteristics of the signal in the transmission direction and / or the reception direction may deviate substantially from “flat behavior”. Then, as shown in FIG. 7, it is interesting to measure the phase deviation and the amplitude deviation at different frequency points. White circles indicate the respective transmission / reception units 20-1, 20-2,. . . , 20-N. Transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N and reception deviations ΔRx−1, ΔRx−2,. . . , ΔRx−N, the phase deviation is not flat as indicated by the solid line. In fact, the solid straight line shows the interpolation between the frequencies (white circles, left y-axis) at which the phase deviation was actually measured. Similarly, transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx-N or reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N are measured at several frequencies, as indicated by a white square (corresponding to the right y-axis) in FIG. 7, between the values measured for the amplitude deviation. Can do.

  Payload signals P-1, P-2,. . . , PN may have a small bandwidth. Each of the transmission / reception units 20-1, 20-2,. . . , 20-N and the frequency dependence of the amplitude deviation and / or phase deviation is determined by the payload signals P-1, P-2,. . . , P-N, the payload signals P-1, P-2,. . . , P-N, it may be sufficient to perform phase correction and / or amplitude correction for phase and amplitude deviations. More precisely, the amplitude compensation and phase compensation are the payload signals P-1, P-2,. . . , PN may be derived only by correction terms that depend on the center frequency. Correction of phase and amplitude measurements at different frequencies (as shown in FIG. 7) can be achieved using correction terms and center frequencies.

  The transmission / reception units 20-1, 20-2,. . . , 20-N amplitude and phase transfer characteristics are represented by payload signals P-1, P-2,. . . , P-N, a different scheme for compensating for phase and / or amplitude may be applied. In the transmission direction, the in-band compensation scheme can be realized using the pre-emphasis unit 135. The predistortion unit 135 includes antenna elements 85-1, 85-2,. . . 85-N, use frequency dependent phase and amplitude deviation results as described with respect to FIG. 7 to obtain substantially “flat” amplitude characteristics and substantially linear phase variation over frequency. And the individual payload signals P-1, P-2,. . . , P-N is deformed in advance. The predistortion unit 135 is provided in the central baseband processing unit 10 or the transmission / reception units 20-1, 20-2,. . . 20-N could be implemented for each transceiver.

  In FIG. 8, a signal P 0 whose phase varies substantially “flat” with respect to frequency enters the pre-emphasis unit 135 from the left. The pre-emphasis unit 135 adds a linear increase amount with respect to the frequency to the signal P0, thereby forming the pre-emphasis signal P1. The pre-emphasized signal P1 is transmitted to the transmitting / receiving units 20-1, 20-2,. . . , 20-N. The pre-emphasized signal P1 has transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N includes a phase variation with respect to frequency, such as “inverting” the phase deviation in ΔTx−N, thus producing a substantially “flat” transmission signal Tx with respect to the phase variation with respect to frequency.

  In the receiving direction, an inverse compensation scheme can be implemented based on an equalizer. FIG. 9 shows in-band received phase compensation with an equalizer 130. A reception signal having a substantially “flat” phase deviation with respect to the frequency is transmitted from the right to the transmitting / receiving units 20-1, 20-2,. . . 20-N. The transmission / reception units 20-1, 20-2,. . . , 20-N imposes a frequency dependent phase variation on the received signal Rx. The modified received signal Rxd whose phase decreases substantially linearly with respect to the frequency is transmitted to the transmitting / receiving units 20-1, 20-2,. . . , 20-N. In order to provide an undistorted received signal whose phase transfer characteristic is substantially “flat” with respect to frequency, the equalizer 130 receives received deviations ΔRx−1, ΔRx−2,. . . , ΔRx−N can be corrected.

  The equalizer 130 includes transmission / reception units 20-1, 20-2,. . . , 20-N or the central baseband processing unit 10.

  The present disclosure further relates to a method 1000 for relaying wireless signals in a mobile communication network.

  FIG. 10 shows a flow diagram of the method 1000. Step 1100 includes generating a global timing signal T. The global timing signal T is at a fixed timing rate Tr. The global timing signal T is generated in response to the base station signal 7 from the base station 5. As described above, the global timing signal T is generated by detecting a rising edge and / or a falling edge of a signal component in the base station signal 7.

  In step 1200, the global timing signal T includes at least one payload signal P-1, P-2,. . . , P-N. In step 1300, payload signals P-1, P-2,. . . , PN are linked to links 40-1, 40-2,. . . , 40-N.

  In step 1400, the transmitting / receiving units 20-1, 20-2,. . . , 20-N and payload signals P-1, P-2,. . . , PN to local timing signals T-1, T-2,. . . , TN are taken out. The global timing signal T is a local timing signal T-1, T-2,. . . , T-N retrieval 1400.

  Step 1500 includes steps of transmitting / receiving units 20-1, 20-2,. . . , 20-N. Step 1600 includes individual local timing signals T-1, T-2,. . . , TN according to payload signals P-1, P-2,. . . , PN relaying. The selectable payload rate Pr can be selected independently from the fixed timing rate Tr.

  Links 40-1, 40-2,. . . , 40-N, the payload signals P-1, P-2,. . . , PN are relayed, it will be understood that the temporal order of data packets reaching the central baseband processor 10 is not preserved. Links 40-1, 40-2,. . . , 40-N are relayed throughout the individual transceivers 20-1, 20-2,. . . , 20-N may also be included. The temporal order of the data packets is determined by local timing signals T-1, T-2,. . . , T-N (see FIGS. 3 and 4).

  FIG. 11 shows details of deviation compensation 1500 between the respective transceiver units. Step 1500 includes method steps on the left for transmission deviation compensation. Corresponding steps of compensation 1500 are shown in the right side reception deviation compensation. First consider the case of transmission. In step 1510Tx, for example, active antenna elements 85-1, 85-2,. . . , 85-N, the combined transmission signals 120Tx-1, 120Tx-2,. . . , 120Tx-N are taken out. The combined transmission signals 120T-1, 120Tx-2,. . . , 120 Tx-N extraction 1510 Tx may be used. In step 1520Tx, transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N are measured. The measurement can be performed using the measurement unit 150.

  In the case of reception, the method includes combining received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N, starting at step 1510Rx. The transmission / reception units 20-1, 20-2,. . . , 20-N or the transmission / reception units 20-1, 20-2,. . . , 20-N only for selected groups, the combined transmission signals 120Tx-1, 120Tx-2,. . . , 120Tx-N and / or the combined received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N may be taken out.

  Step 1520Rx includes respective combined received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N and at least one payload signal P-1, P-2. . . , PN, received deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N. Typically, the reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx-N are the combined received signals 120Rx-1, 120Rx-2,. . . , 120Rx-N and the same transmitter / receiver 20-1, 20-2,. . . , 20-N payload signals P-1, P-2,. . . , P-N.

  Step 1530 includes calculating compensation. For transmission, step 1530 includes transmission compensation 200Tx-1, 200Tx-2,. . . , 200TX-N calculation 1530Tx. Transmission compensation 200Tx-1, 200Tx-2,. . . , 200Tx-N includes transmission phase compensation, transmission amplitude compensation, and transmission delay compensation. In the calculation of 1530Tx, a frequency-dependent correction term for the pre-emphasis unit 135 may be generated as described with reference to FIG.

  In the case of reception, step 1530 includes reception compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N calculation 1530Rx. The receive compensation calculation 1530Rx may include frequency dependent compensation implemented by providing a correction term to the equalizer 130 as described with respect to FIG. Reception compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N includes phase reception compensation, amplitude reception compensation, and delay reception compensation. The calculation 1530Rx includes reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N measurement 1520Rx. As described with respect to FIG. 7, the measurements may include frequency dependent measurements and interpolation.

  Step 1540Tx includes arbitrary transmission deviations ΔTx-1, ΔTx-2,. . . , ΔTx−N to compensate for transmission compensation 200Tx−1, 200Tx−2,. . . , 200Tx-N as payload signals P-1, P-2,. . . , P-N.

  As shown in FIG. 9, the step 1540Rx uses an equalizer 130, for example, to receive arbitrary reception deviations ΔRx-1, ΔRx-2,. . . , ΔRx−N to compensate for reception compensation 200Rx−1, 200Rx−2,. . . , 200Rx-N on the received signal.

  Step 1540Rx includes reception compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N to individual antenna elements 85-1, 85-2,. . . , 85-N.

  Step 1500 includes individual transmitting / receiving units 20-1, 20-2,. . . , 20-N at a time or more than one transceiver 20-1, 20-2,. . . , 20-N may be executed simultaneously. Step 1500 includes transmission / reception units 20-1, 20-2,. . . , 20-N, only one of the transceivers 20-1, 20-2,. . . , 20-N, it will be appreciated that step 1500 needs to be repeated several times to fully compensate for the deviation.

  Method 1000 allows payload signals P-1, P-2,. . . , PN, digital links 40-1, 40-2,. . . , 40-N, a substantially matched relay in the active antenna array 1 is realized.

  Further, the present disclosure teaches a computer program product that includes a non-transitory computer-usable medium having control logic stored therein for causing a computer to manufacture an active antenna array for the mobile communication network of the present disclosure. The

  Further, the present disclosure has been stored internally for causing a computer to relay a radio signal within the mobile communication network, as described using the method 1000 for relaying a radio signal within the mobile communication network of the present disclosure. The present invention relates to a computer program product including a non-transitory computer-usable medium having control logic.

  While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example and not limitation. It will be apparent to those skilled in the art that various modifications can be made to these forms and details without departing from the scope of the invention. (E.g., within or coupled to a central processing unit ("CPU"), microprocessor, microcontroller, digital signal processor, processor core, system on chip ("SOC"), or any other device) In addition to using hardware, for example, software (eg, computer-readable code, program code) located on a non-transitory computer-usable (eg, readable) medium configured to store software And / or instructions arranged in any form, such as source, target language or machine language). Such software may enable, for example, the functionality, manufacturing, modeling, simulation, description and / or testing of the devices and methods described herein. For example, this can be accomplished by using a common programming language (eg, C or C ++), a hardware description language (HDL) including Verilog HDL, VHDL, etc., or other available programs. it can. Such software can be located on any known non-transitory computer-usable medium, such as a semiconductor, magnetic disk, or optical disk (eg, CD-ROM, DVD-ROM, etc.). The software is arranged as a computer data signal embodied in a computer-usable (eg readable) transmission medium (eg carrier wave or any other medium including digital, optical or analog based media). You can also. Embodiments of the present invention provide software describing a device described herein and then provide the device by transmitting the software as a computer data signal over a communication network including the Internet or an intranet. A method may be included.

  The apparatus and method described herein may be included in a semiconductor IP core, such as a microprocessor core (e.g., embodied in HDL) and converted to hardware during integrated circuit production. Will be understood. Also, the apparatus and method described herein may be embodied as a combination of hardware and software. Therefore, the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents.

1a Active antenna array 5 Base station 7 Base station signal 10 Central baseband processing units 20-1, 20-2,. . . , 20-N transceiver unit 25 duplexer 25-1, 25-2,. . . , 25-N duplex filters 40-1, 40-2,. . . , 40-N link 50 central clock section 60-1, 60-2,. . . , 60-N transmission amplifiers 70-1, 70-2,. . . , 70-N receiving amplifiers 85-1, 85-2,. . . , 85-N active antenna elements 90-1, 90-2,. . . , 90-N adjusters 95-1, 95-2,. . . , 95-N processing elements 110-1, 110-2,. . . , 110-N feedback paths 120-1, 120-2,. . . , 120-N feedback signals 120Tx-1, 120Tx-2,. . . , 120Tx-N Combined transmission signal 120Rx-1, 120Rx-2,. . . , 120Rx-N Combined received signal 150 Measurement unit 200Tx-1, 200Tx-2,. . . , 200Tx-N transmission compensation 200Rx-1, 200Rx-2,. . . , 200Rx-N reception compensation ΔTx-1, ΔTx-2,. . . , ΔTx−N Transmission deviations ΔRx−1, ΔRx−2,. . . , ΔRx-N reception deviations P-1, P-2,. . . , PN payload signals T-1, T-2,. . . , TN Local timing signal

Claims (17)

An active antenna array for a mobile communication network,
A baseband unit coupled to the base station;
A plurality of transceiver units each terminated by at least one antenna element;
And at least one link coupling each of the plurality of transmitting / receiving units to the baseband unit,
The at least one link is a digital link, configured to relay a payload signal at a selectable payload rate, and further configured to relay a timing signal at a fixed timing rate, and at the selectable payload rate An active antenna array in which the timing signal is embedded in the payload signal.   The active antenna train of claim 1, wherein the at least one link is configured to relay the payload signal using a variable packet length.   The active antenna array according to claim 1, further comprising a central clock unit that supplies the timing signal in response to a base station signal received from the base station.   The active antenna array according to claim 1, comprising a plurality of local timing units configured to extract a local timing signal in response to the timing signal.   The active antenna array according to any one of claims 1 to 4, further comprising a plurality of transmission amplifiers for amplifying transmission signals transmitted by the respective transmission / reception units.   The active antenna array according to claim 1, further comprising a plurality of reception amplifiers for amplifying reception signals received by the respective transmission / reception units.   7. At least one adjustment unit configured to add at least one of variable delay, variable phase weighting and variable amplitude weighting to signals passing through each of the links. The active antenna array according to any one of the above.   Each of the transmission / reception units includes at least one processing element for signal processing, and the at least one processing element includes a digital filter element, an analog filter element, a duplex filter, a digital / analog converter, and an analog / digital converter. The active antenna array according to claim 1, wherein the active antenna array is selected from the group consisting of an equalizer and a mixer.   One comprising at least one feedback path from an individual antenna element to a measurement unit, wherein the feedback path relays a feedback signal, the feedback signal being combined from a signal transmitted by the individual antenna element Or a plurality of combined transmission signals or at least one of one or more combined reception signals combined from signals received by the individual antenna elements. The active antenna array according to any one of the above. The measuring unit is configured to measure transmission deviations accumulated when transmitting using the individual transmitting / receiving units;
The active antenna array according to claim 9, wherein the transmission deviation includes at least one of an amplitude deviation, a phase deviation, and a delay deviation. The measuring unit is configured to measure a reception deviation accumulated when receiving using each of the transmitting and receiving units;
The active antenna array according to claim 9 or 10, wherein the reception deviation includes at least one of an amplitude deviation, a phase deviation, and a delay deviation. A method for relaying a radio signal in a mobile communication network, comprising:
In response to the base station signal received from the base station, generates a global timing signal at a fixed timing rate,
Embedding the global timing signal in at least one payload signal at a selectable payload rate;
Transferring the at least one payload signal over at least one link;
Extracting at least one local timing signal for at least one transceiver from the global timing signal;
Relaying the at least one payload signal according to individual local timing signals;
The method wherein the selectable payload rate is selectable independently of the timing rate.   The method of claim 12, further comprising compensating for a deviation between each of the transceiver units. Compensating said
Take the combined transmission signal,
Measuring a transmission deviation between each said combined transmission signal and said at least one payload signal;
Calculate transmission compensation,
14. The method of claim 13, comprising imposing transmission compensation. Compensating said
Take the combined received signal,
Measuring a reception deviation between each of the combined received signals and the at least one payload signal;
Calculate reception compensation,
14. The method of claim 13, comprising imposing reception compensation. A computer program product comprising a non-transitory computer-usable medium having internally stored control logic for causing a computer to produce an active antenna array for a mobile communication network, the active antenna array comprising:
A baseband unit coupled to the base station;
A plurality of transmission / reception units terminated by at least one antenna element;
And at least one link coupling each of the plurality of transmitting / receiving units to the baseband unit,
The at least one link is a digital link, configured to relay a payload signal at a selectable payload rate, and further configured to relay a timing signal at a fixed timing rate, and at the selectable payload rate A computer program product in which the timing signal is embedded in the payload signal. A computer program product comprising a non-transitory computer-usable medium having internally stored control logic for causing a computer to relay a radio signal in a mobile communication network, the control logic comprising:
First computer readable program code means for causing the computer to generate a global timing signal at a fixed timing rate in response to a payload signal received from a base station;
Second computer readable program code means for causing the computer to embed the global timing signal in at least one payload signal at a selectable payload rate;
Third computer readable program code means for causing the computer to transfer the at least one payload signal over at least one link;
Fourth computer readable program code means for causing the computer to extract at least one local timing signal for at least one transceiver from the global timing signal;
Fifth computer readable program code means for causing the computer to relay the at least one payload signal in accordance with each local timing signal;
A computer program product wherein the selectable payload rate is selectable independently of the timing rate.

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